Method of burning oil as city gas



Jan. 8, 1935. c. B. HILLHOUSE ,9 7

METHOD OF BURNING OIL AS CITY GAS Filed Jan. '7, 1933 INVENTOR,

. BY Clzarlesfiflr'llho use,

TORNE Y. n

Patented Jan. 8, 1935 UNITED STATES" PATENT OFFICE METHOD OF BURNINGfOIL AS crrY GAS Charles B. Hillhouse, New York, N. Y. Application Janu r7, 1933, Serial No. 650;?07

I 3 Claims. (Cl.158117.5)

My invention relates to a method and appaw ratus for combustion and hasparticular reference to a method and apparatus wherein a por-.

tion of the fuel to be burned, preferably oil or other hydrocarbon,iscaused tocombust in a man-nerto produce combustible gases and thesegases are mixed withanother portion of fuel and sufiieient' air andburned to produce the main zone of combustion.

The main object of my invention is to burn predetermined separateportions of fuel so that its ases' final combustion willhaveapproximately the same composition and flame temperature as a known gas;for example; city oil-water gssor, according to a modification,acetylene.

Anotherohject isto provide ametho'd whereina portion of the fuel,preferably oil, is burned as a preliminary step with insuflicient air toproduce gasificatioh of that ortion, and then mixingthe highly heatedgas products-intimately with another'poition of fuel and also air toproduce-the the burner is admitted through air supply conmain combustionzone. I

This method is carried out by feeding into an auxiliary section of theburner, without an accorhpanying'oxidizing' medium; a suitable portioiiof the oil to produce a gas having the'p'rcentage of carbonmonoxide usually found-in'city water gas. In its axial passage outward,air is added to this oil to partially burn the same, which furnishesheat for; preheating and cracking following portions of the oil? Then asthe stream of. hotgasified -fuel,-CO and 1-12,. passes from thisauxiliary section-of the-burner, anothen portion of the fuel oil issprayed into itand to- 88 gether they pass into the mainbuinr-section towhich air for complete combustion has been supplied. in this manner, thecomposition of gases and flame temperature of the main or finalcombustion zone may be madeto closely approxi mate that produced when acity oil water" gas is burned. By varying the proportion or kind of oilwhich is fed into the auxiliaryse'ction of the burner to produce carbonmonoxidacombustion zones of other characteristics could be producedwhich would vary more or less from that prodiiced by burning a city gas.

According to a variation in the type of fuel used-and with the sameprocess wherein solid carboil or preferably chemicalcarbon that has beendissociated from oil or gas is fed into the main burner sectionor streamof gases leading thereto instead of the other portion of oil as abovedescribed. a flame simulating an acetylene flame can be cheaply roduced.According tea variation or the method, natural gas may be used as thecarbonaceous material to be mixed with the gases formed in the auxiliaryburner section and: burned to complete combustion with air.

The apparatus disclosed is a modification of that shown in my Patent No.1,852,968, issued April 5, 1932, for Burning solid fuel, but it isherein applied to the combustion of fiuid'substances.

In the accompanying drawing- Figure 1 is an elevation in cross-sectionof an oil burner constructed to carry out the method described;

Fig.2 shows, on a reduced sca1e,.a cross-se'c-- tionon line 2-2 of Fig.1; and I Fig. 3 shows a modification of the device of Fig. 1 1' In thepreferred form of apparatusshown, there are provided spaced inner andouter walls I and 2 which form the main casing of theburner; which wallsare held spaced from each other by supports or stays 3. The total airsupply to min which is provided with a control valve 5. The greaterportion of this air passes upwardly through the space 6 between thewalls 1 and 2 to a point adjacent the upper end of the wall 1 where theair will strike the inwardly turned throat '7 formed on the upper end ofthe wall 2; The air is deflected by this throat '7 towards the axis ofthe auxiliary burner section 8.

"A portion of the oil from main oil supply conduit 9 is admitted withoutair from a branch conduit 10 through an inlet 11, the tip of which maybe provided with a suitable spray nozzle, into the chamber formed bywall 1. The conduit 10 is arranged to direct the oil tangentially towall 1 and-downwardly within the chamber 8.. In order to prevent oilfrom being drawn upwardly, spiral grooves 12 are formed on the innerface of the wall 1. The bottom wall of the chamber 8 is curved at 13 todirect the heated oil or cracked gases inwardly and upwardly along thecentral axis of the chamber 8. A portion ,of the air from inlet 4 is nowadmitted by a control valve 14 through an air inlet 15 arrangedcentrallyof the bottom of chamber 8. The oil from inlet 11 is whirled helicallyand downwardly around the axial combustion zone in the chamber land ispreheated by this axial zone and is, in part, cracked. The air frominlet 15- is insurlicient to support complete combustion in chamber 8and .the partial combustion of oil therein produces mainly carbonmonoxide and hydrogen gases which are ejected axially towards the upperend of the chamber 8. The main supply of oil is admitted through one ormore conduits 16 which feed from a manifold 17 which, in turn, issupplied from the oil conduit 9 through a pipe 18. Each conduit 16 isarranged at an angle upwardly to direct the oil into the stream offormed gases which is emitted axially from chamber 8. The outlet tip ofeach conduit 16 may be formed as an oil atomizer in the usual manner.Control valves 19 and 20, respectively, are provided to regulateadmission of oil from conduits 10 and 16.

According to the modification of Fig. 3, each conduit 16 is suppliedwith finely divided solid carbon fed from a hopper 21 by a screwconveyor 22. carry the carbon from the conveyor to the tip or outlet ofeach conduit 16 while a valve 24 is provided to control this injector.If desired, the solid carbon feed of Fig. 3 may be applied-to theapparatus shown in Fig. 1 as an auxiliary or solid-carbon feed in amanner to permit a-supply of either or both oil and solid carbon to themain combustion zone selectively or simultaneously to vary the characterof combustion in that zone.

Under certain conditions, it may be desirable to supply a differentgrade of oil to chamber 8 than to conduits 16. To this end, the mainsupply of oil will be admitted from a supply pipe 9' through a valve 25to manifold 17. A valve 26 in the pipe 18 will be closed and any otherkind of oil desired will be supplied to the conduit 9. If it is desiredto burn natural gas in the main flame, such gas will be fed to manifold17 from the conduit 9'.

In the operation of the apparatus in accordance with my novel method,for each 4 gallons of fuel oil supplied from the conduit 9, I prefer tofeed 1 gallons through the inlet 11' and three gallons through theinlets 16. The oil from inlet 11 is whirled helically downwardly closelyadjacent the wall of chamber 8 and around the axial zone of combustion,the heat of which is absorbed by the current of oil whereby a portion ofthis oil is preheated and cracked or vaporized before it is deflected bythe curved bottom 13 into the axial combustion zone. Air from inlet 15is admitted in insufficient amount to support complete combustion,thereby causing the carbon portion of this oil to unite with oxygen toproduce CO and H2. The spiral grooves 12 act to prevent upward flow ofoil along the chamber wall.

The gaseous products are discharged from the upper open end of chamber8. The valves 20 are set to permit oil under pressure from manifold 17to be sprayed from conduits 16 into the issuing stream of hot gases fromchamber 8 which will crack or gasify that oil before reaching the maincombustion zone, while warm air from the space 6 in amount controlled byvalves 5 and 14, is deflected from the surface 7 into the stream of oiland gases, whereby to support a main flame or zone of combustion whichwill issue from the burner nozzle. This flame corresponds closely to aflame produced by burning a city oil-water gas both as to compositionand temperature. In a modified form, this method may be employed toproduce a flame which corresponds closely to a flame produced by burningacetylene. To this end, the conduits 16 as shown in Fig. 3 will besupplied with solid carbon and this carbon in its finely divided formwill be injected by means of as injector 23 to mix with air from thespace 6 and hot gases from the chamber 8.

An air or steam injector 23 serves to r In order to illustrate withfigures to compare the composition of the oil flame as above producedwith that of New York city oil-water gas, the common unit of 1000 cubicfeet of gas of 520 B. t. u. will be taken. Such gas is made from threegallons of partly cracked oil mixed with straight water gas made fromcoke. The composition of New York city gas is:

Saturated hydrocarbons 29% Efremthree Unsaturated hydrocarbons--- 15%gallons oil Hydrogen -Q. 27% I I Carbon monoxide 27% FromavgaterNitrogen 2% g The following will be the composition of the oil flamewhen made as described from fuel oil:

Saturated hydrocarbons 29% From three Unsaturated hydrocarbons 15%gallons oil Hydrogen"; 27% From 1 gallons Carbon monoxide 27% gasifiedfuel oil For the gasified oil flame, there will also be an excess ofnitrogen in the gases of combustion of about 10% over'the nitrogen incity-gas combustion, but, as it enters the final flame at upwards of1500 F. and the sensible heat in the hydrogen and oxygen is added to theflame, there will be no drag from .that nitrogen, thatis, no heatwill bewithdrawn from new combustion to raise'the temperature of this highlyheated nitrogen.

If the oil to be .used does not have a high enough proportion of carboncompared with hydrogen in its composition, a mixtureinto it of ahydrocarbon with a higher proportion of flnely divided solid carbon oreven straight carbon may be made'to produce the exact proportionof COfrom the first portion of the oil treated in the auxiliary burnersection withoutincreasing the percentage of hydrogen. I

Both city gas and my gasified oil method use the same quantity of oilfor. enrichment-namely, three gallons. In city gas, this oil is crackedoutside; whereas, in my method, it is partly cracked by the hotmadegases. v r v -The following figures will illustrate and compare aflame produced by burning one gallon of oil gasified as described andsolid carbon with a flame run from y2'75 cubic feet of acetylene.

Acetylene 17 lbs. C+ 1% lbs. H -labsorbed heat.

275 cu. ft.X11. 90 air=3557 cu. ft. of gases of combustion.

275 cu. ft. X 1,483= 407,825 Bpt. u.

When one gallon oil gasified as described is burned with 21 /2 lbs.solid carbon, we have:

21% lbs. CX 3,225 cu. ft.

Gases of combustion=3,891 cu. ft.

280 Cuft. 340 B.t.l.1.= 95,200 B-t-ll.

throat '7 or into the air for combustion surrounding the tip which flowsfrom the space 6.

My improved process of burning gasified oil will benefit large users ofcity gas by bringing the cost down to an oil basis and will benefitlarge users of oil by raising the flame temperature without preheatingthe air for combustion. It also obviates the difficulty of making watergas from oil and steam because of the unwieldy proportion of hydrogenmade. When solid carbon is used as a portion of the fuel used in mymethod, it Will produce a combustion that corresponds closely to anacetylene flame and at a fraction of the present cost of making andburning acetylene.

The apparatus disclosed to perform the method claimed is intended toillustrate a preferred form of apparatus. Variations may be made thereinwithout altering the broad process carried out. For example, similarresults can be obtained by causing the oil to move helically upwardlyand the axial air stream downwardly or in any direction desired. Suchmodifications are contemplated as will be embraced within the scope ofthe appended claims.

What I claim is:

1. The method of burning fluid fuel which consists in conducting aportion of oil in one direction along a burner wall and in the presenceof a flame spaced from said oil, maintaining the oil and flame in arelation to heat said oil and partially vaporize or gasify the same,directing the oil and gas in another direction into said flame, addingsufficient air to partially combust the oil and gas to form gaseousproducts, mixing the hot gaseous products with liquid fuel to gasifysame and burning the final mixture with secondary air sufiicient forcomplete combustion.

2. The method of burning fluid fuel which consists in conducting aportion of oil in one direction in a helical path along a burner walland in the presence of a flame positioned axially of said path wherebyto partially preheat and crack the oil by heat absorbed from the flame,then directing the oil in another direction into said flame, feeding airto said flame in amount suflicient for partial combustion of the heatedoil to form carbon monoxide and hydrogen gases, mixing fluid fuel withthe heated gaseous products and burning the mixture with secondary airsufiicient for complete combustion.

3. A method of burning fluid fuel which consists in preheating a portionof oil in a burner and then reducing it to carbon monoxide and hydrogenby partial combustion without deposit of carbon, then mixing into thecarbon monoxide and hydrogen while in a heated state a portion ofgaseous fuel and then burning this mixture with sufiicient air forcomplete combustion.

CHARLES B. HILLHOUSE.

